Equity (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017	Apr. 04, 2017
Class of Stock [Line Items]
Common stock, par value	$ 0.20	$ 0.20
Common stock, shares issued	54,046,361	52,880,134
At-the-Market Common Stock Program [Member]
Class of Stock [Line Items]
Common stock, par value			$ 0.20
Aggregate Offering Price			$ 100,000
Commission of the gross sales price by share paid percentage			2.00%
Common stock, shares issued	787,547
Proceeds from issuance of common stock, net of issuance costs	$ 18,623